Giant Asteroid Makes Christmas Eve Flyby

This simulated orbital view shows the view from asteroid SD220 as it glides by Earth and the inner solar system.

Photograph by Andrew Fazekas, SkySafari, NASA

It looks like Christmas Eve will be a bit busier than usual as a wayward asteroid joins Santa and his reindeers trekking across our Earth skies.

A giant space rock known as 2003 SD220, estimated to be 1.2 miles (2 kilometers) across, will be making its closest approach to Earth on December 24, zooming at 17 miles (27 km) per second. But, no worries: that “close approach” will miss us by 6.7 million miles (11 million kilometers)—about 28 times the distance separating the Earth and the moon.

To the chagrin of astronomers, some reckless media reports have implied the asteroid could cause earthquakes across the globe.

There is no scientific evidence whatsoever that any sized space rock swinging by our world could ever trigger even the tiniest seismic activity. The prophets of space doom seem to forget that the Earth’s moon is 27 times closer to our planet than SD220, and over 1,700 times larger in diameter.

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The asteroid 2003 SD220 will be gliding through the Virgo constellation near its brightest star, Spica, and the planet Mars on Christmas Day.

Skychart by A. Fazekas, SkySafari

While some asteroids, known as Near Earth Objects (NEOs), do pose a threat of colliding with our planet, NASA says the orbit of SD220 won’t pass within a dangerous distance for at least the next 200 years.

Meanwhile, there will be other opportunities in the near future to get a close up look at SD220. This flyby will be just the first of five over the next 12 years, with the next one in 2018.

Each event offers astronomers an amazing opportunity to advance our knowledge about these barnstorming asteroids. By bouncing radar signals off the surface of SD220, we’ll be able to gather valuable data such as its shape, dimensions, and spin. Already, the Arecibo Observatory in Puerto Rico has gotten an early look and astronomers have likened its elongated form to a chicken tender. NASA’s Goldstone Antenna in California will also be on the case this week.

At its closest approach, SD220 will be no brighter than magnitude 15, making it visually impossible to catch with even large backyard telescopes. However, advanced photo hounds with the right equipment may be able to snag a digital image of the rocky interloper gliding across the sky against the background of fixed stars.

Best bets on hunting it down will be in the pre-dawn skies of Christmas Day, low in the eastern sky near the bright naked eye planet Mars and Spica, the lead star in the constellation Virgo.